Answer:
There are two men by the name of Mephibosheth in the Bible, both in 2 Samuel. The less prominent one was a son of King Saul; he was delivered by David to the Gibeonites to be hanged in retaliation for Saulís earlier slaughter of a band of Gibeonites (2 Samuel 21:1-9).

The other Mephibosheth was the son of Jonathan, who was the son of King Saul and a special friend of King David. When Mephibosheth was five years old, his father Jonathan was killed in battle. Fearing that the Philistines would seek to take the life of the young boy, a nurse fled with him to Gibeah, the royal residence, but in her haste she dropped him and both of his feet were crippled (2 Samuel 4:4). He was carried to the land of Gilead, where he found refuge in the house of Machir, son of Ammiel, at Lo-debar.

Some years later, when King David had conquered all of Israelís enemies, he remembered the family of his friend Jonathan (2 Samuel 9:1), and, wishing to display his loving loyalty to Jonathan by ministering to his family, David found out that Mephibosheth was residing in the house of Machir. So he sent royal messengers there, and brought Mephibosheth and his infant son Micah to Jerusalem, where they resided from that point on (2 Samuel 9).

Later, when David invited the young boy to be part of his court, he entrusted the family property to a steward, Ziba. During Absalomís rebellion, Ziba tried unsuccessfully to turn David against Mephibosheth. Upon the kingís return to Jerusalem, Mephibosheth vindicated himself and was allowed to remain in the kingís house (2 Samuel 16:19).